Tire vulcanizing apparatus



July 31, 1945.

T. P. BACON, JR'.

` July 31, 1945. 1 Ty, P. BACON. JR l TIRE VULCANIZING APPARATUS Filed Deo. 7, l1942 2 Sheets-Sheet 2 INVENTOR THOMAS l? BAc'o/v, Je BY W M1422 Patented July 31,y 1945 UNITED STATES PATENT OFFICE 2,380,380 'rmE vULcANTzlNG APPARATUS Thomas P. Bunn, Jr., oakland, cam.

Application December 7, 1942, Serial No. 468,319

(c1. 11i-1s) 2 Claims.

This invention relates to an apparatus for vulcanizing treads on tires. n

An object of this invention is to'provide a tire rim for use in curing tires, which rim is so formed as to prevent excessive bulging or lateral distortion of the tire while in the curing mold, and also to 'carry away heat from the tire to such a degree as to prevent overcuring of the weaker sides of the tire and thus to permit the curing of the tire with standard inner tubes instead of special curing bags now in use.

Another object of the invention is to provide a mold cavity or matrix for curing molds with flanges extended in'such proximity of oppositely extended side iianges of a curing rim as tc maintain the tire in substantial normal rounded position and to preventV the lateral distortion or excessive bulging of the tire during the curing operation. Y

Another object of the invention is to provide a system of passages in the curing cavity of the matrix of the mold so arranged as to carry away liberated gases or air from the tread surface during curing and also to form a protuberant design on the traction surface of the tire.

Another object of this invention is to provide a tire curing rim and mold which is highly useful.

dened in the following claims; hence I do notlimit my invention to the exact arrangements andV combinations of the said device and parts as described in the said specification, nor do I confine myself to the exact details of the construction of the said parts as illustrated in the accompanying drawings.

With the'foregoing and other objects in View,

" rim in combination with the matrix in a tire mold.

Fig. 2 is a fragmental perspective view of the finished tire, indicating the design lines formed on the surface of the tire by the gas relieving Y passagesoi the mold, and

Fig. 3 is a plan Aview of the mold and of the curing rim in curing position.

In the herein illustrative embodiment of m invention, I show a full circle mold made of three arcuate sections 6 which complement each other into a circular mold when closed. The mold sections 6 are heated in any suitable manner. The sections are hinged togetherat 1 and are clamped in curing position by a suitable clamping device shown in Fig. 3 at 8.

Inside of the mold sections 6 are matrix sections 9 which may be of any usual construction, but of slightly smaller inner diameter than the tire diameter when fully inflated.- 'I'he distinguishing feature of the matrices in this Ymold reside in the arrangement of side flanges II which extend to a substantial distance over the sides of the tire indicated in broken lines at l2 in Fig. 1. These flanges I I taper to a narrowedge as shown. Inside of the curing cavity I3 of the matrices 9, is a system of gas relieving passages I4.` These passages I4 consist of groovesin the curing cavity I3. Certainofthe grooves extend circumferentially so as to form continuous circumferential grooves I4 around the entire periphery of the tire. Transverse grooves Il' extend across the entire arcuate width of the curing cavity I3 and to the edges of the flanges II. By this system of grooves Il and I4', the air trapped in the curing cavity I 3 and the gases developed during the curing of the rubber are conducted along the circumferential grooves I4 and then through the transverse grooves Il out from the curing cavity I3 at the narrow edges of the matrix flanges Il. TheV gases and oxides forced out of these grooves Il and I4' by the pressure of the rubber during curing, are replaced by the rubber tread material and form a tread design on the periphery of the tire cured in such matrices. It is to be noted that A adjacent the inner edges of the matrix flanges Il there are provided a plurality ofcircular grooves I4 in close proximity so as to provide the ridges whichfusually indicate the termination of the tread design at the sides of the tire. Y The protu-berances I6 thus created on the surface of the tire are indicated in Fig. 2.

The curing rim illustrated in this application 1s shown to cooperatefwith the matrices 'of this particular type of mold, but itis understood that. the herein curing rim may be used in connection with various other types of molds and matrices. This curing rim is made of a pair/tof circular sections il..A Each section has a rim I8 and a circular ange I9 extending all around the outer edge of the rim i8. The rim I8 has its outer peripheral face 2l formed so that it inclines from the flange I 9 toward the center edge of the curing rim I8. The flange I9 has a corner 22 thereon joining the outer end of the inclined rim face 2I. When the tire I2 is placed on such rim and is inflated, then the beads 23 of the tire I2 are wedged outwardly into the corner formed between the flange face 22 and the rim face 2l. This facilitates the putting of the tire in the rim and also rmly wedges the tire beads in place when the tire is inflated. The inner'suriace of each flange I9 is curved at 24 so as to substantially conform to the curvature of the tire above the bead and to lead at a true radius of said tire curvature to the bead. The flange I9 tapers outwardly to a comparatively narrow edge 26, and is of such height that the edge 26 is located at about the portion of the sides of the tire I2 where the tire is the widest when inflated.

In order to accelerate the carrying away of the heat from the sides of the tire, the rim anges I9 are provided on their outer periphery with cooling fins 2l. In this illustration the cooling iins 2l are arranged in concentric circles. It was found that curing rims so constructed protect the tire against excessive bulging or distortion and also cool the sides of the tire to such an extent that the regulation inner tube can be used while the tire is cured without any injury either to the tube or to the tire. In fact, in actual practice the usual curing temperature of the tire was reduced by the use of these cured rims by as much as 130 Fahrenheit, namely, from about 220 Fahrenheit to about 90 Fahrenheit.

The annular rim sections are held together by bolts 28 which extend transversely at spaced points of the innerperiphery of the respective rims I8. These bolts 28 work in lugs 22 which extend in aligned positions from the inner peripheries of the respective rims I8, as shown.

The herein described curing rims are adjustable as to width by the insertion of spacer rings 3| which can be placed as desired between the meeting edges 32 of the rim sections I8. The curing rims herein are made of a good heat conducting material, such as aluminum.

I claim:

1. A tire mold forming an annular curing cavity and having a system of intercommunicating escape grooves in the walls of said curing cavity including circumferential grooves and transverse grooves, said transverse grooves intersecting said circumferential grooves and extending across said cavity to and through the inner peripheral edges ofsaid curing cavity to conduct gaseous substances to the outside from between the walls of said curing cavity and the surface of the tire therein and to mold a traction design on said tire surface.

2. A tire mold forming an annular curing cavity and having a system of intercommunicating escape grooves in the walls of said curing cavity including circumferential grooves and transverse grooves, said transverse grooves intersecting said circumferential grooves and extending across said cavity to and through thel inner peripheral edges of said curing cavity to conduct gaseous substances to the outside from between the walls of said curing cavity and the surface of the tire therein and to mold a traction design on said tire surface, a set of circumferential grooves being located at each inner peripheral edge of the curing cavity to form terminating ridges for the tread design, said sets of grooves being also intersected by said transverse grooves.

THOMAS P. BACON, Ja. 

